Until now in order to melt and pour strongly reactive and high-melting metals and alloys, vacuum consumable-electrode arc furnaces and electron beam furnaces have been used.
Vacuum consumable-electrode arc furnaces have, besides their well-known advantages a series of disadvantages for melting and pouring strongly reactive and high-melting metals and alloys, namely: great difficulty in producing high temperatures, the need to replace consumed electrode stubs with ready-made electrodes, great difficulty in controlling the melting process, and complex vacuum-tight installations.
Electron beam furnaces also have a number of disadvantages: they require separate chambers for producing the electron beam and for the melting and pouring process; they require two complex vacuum installations (capable of sustaining vacuums to 10.sup.-5 torr) corresponding to the two chambers; the electromagnetic focussing of the electron beam is very complicated and considerable losses through evaporation occur because of the high vacuum.